Honing machine



March 19, 1957 M. c. HUTTo 2,785,512

HoNING MACHINE Filed Dec. 2, 1952 6 Sheets-Sheet 1 FJ'Q. 1.

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United States Patent O HONING MACHINE Marsden C. Hutto, Detroit, Mich.

Application December 2, 1952, Serial No. 323,66?

Claims. (Cl. 51-l57) This invention relates to a honing machine and more particularly to a machine for honing radially expansible circular articles, such as piston rings.

This application is an improvement on the honing metlr od and apparatus set forth in my Patent No. 2,530,615 dated November 2l, 1950.

Particularly with piston rings, it is desirable that they be accurately finished so as to engage continuously and accurately the wall of the surrounding cylinder while pressed against the cylinder wall uniformly throughout their length. Such finishing operations can be performed by moving the piston rings relative to honing surfaces engaging the peripheries of such rings. If the rings are clamped to the propelling mechanism so as to be incapable of expanding during the honing thereof, the surfaces are not accurately finished to the exact shape or contour that they must have in order to fit tightly and continuously the walls of the cylinder when they are free to expand normally.

It is also desirable that the honing of the piston rings proceed as rapidly as possible to the end that the piston rings can be honed individually, or in small groups, such as a pair, thereby to avoid the necessity of assembling the piston rings in gangs preparatory to honing.

It is also desirable that the piston rings be capable of being, individually or in pairs, rapidly removable from a stack of such piston rings and automatically fed to the honing mechanism and removed therefrom thereby to reduce the labor involved in honing piston rings individually or in pairs.

It is accordingly one of the principal objects of the present invention to provide a honing machine in which the piston rings are rapidly honed to a contour which will continuously and accurately engage the wall of the cylinder in which the piston rings are fitted. Such contour is provided by supporting the rings during honing expander ring for the piston ring being ground the peripheral surfaces of the piston ring are honed under sub stantially the same conditions of confinement and resilient expansible stress as obtain when 'the rings are subsequently used in a cylinder, and the rapidity of honing is greatly augmented by the pressure exerted by the rubber expander ring in augmenting the expansive pressure of the rings against the honing surface.

Another object is to provide such a honing machine in which the piston rings are honed individually or in pairs thereby to avoid the time and labor spent in assembling the rings in gangs upon a suitable fixture and also to avoid the errors of misalinement and tit incident to such assembly.

Another object is to provide such a honing machine in which the rings are rapidly processed and are automatically fed from a stack of rings to the honing parts which auto- 2,785,512 Patented Mlar. 19, 1957 lCC 2 matically hone the rings and in which the honed rings are automatically removed from the machine.

Another object is to provide such a honing machine in which the honing stones are very easily and uniformly adjusted inwardly as wear takes place on their working surfaces.

Another object of the invention is to provide a very simple built-in stone dressing tool and which, following each adjustment, automatically dresses the working surfaces of the honing stones to a cylinder concentric with the honing axis.

Another object of the invention is to provide a very simple and effective mechanism for positively ejecting the honed rings from the piston ring clamping member carrying the rubber expander ring so that there is no danger of a honed piston ring clinging to any of the honing parts.

Another object is to provide such a high speed honing apparatus which is of simple construction and which will stand up under conditions of severe and constant use without getting out of order or requiring repairs.

Other objects and advantages will be apparent from the following description and drawings in which:

Fig. l is a fragmentary side elevational View of a honing machine embodying the present invention.

Fig. 2 is an enlarged horizontal section tak-en generally on line 2 2, Fig. l.

Fig. 3 is a vertical fore-and-aft section taken generally on line 3-3, Fig. 2.

Fig. 4 is a fragmentary enlarged view similar to Fig. 3 and showing on an enlarged scale the connection between the piston ring conveying disk and its hub cap with the sleeve on which it is mounted and the manner in which an oil seal is provided between these parts and the table along which the piston rings are moved.

Fig. 5 is an enlarged fragmentary section similar to Fig. 3 and particularly illustrating in greater detail the manner in which the piston rings are positively stripped from the honing parts after they have been honed.

Fig. 6 is a fragmentary horizontal section taken generally on line 6 6, Fig. 5 and with parts broken away to illustrate the mounting of the holder for the cutting tool or diamond used in dressing the working faces of the honing stones.

Figs. 7 and 8 are horizontal sections taken generally on thecorrespondingly numbered lines of Fig. 3.

Fig. 9 is a vertical section through the reservoir which contains an air filled bladder and which supplies the back pressure against the parts during honing.

Fig. l0 is an enlarged fragmentary view similar to Fig. 5 and in particular illustrating the condition of the rubber expander ring when the piston ring or rings are first engaged bythe vertically reciprocating clamping plates.

Fig. ll is a View similar to Fig. l() and showing the manner in which the piston ring or rings are contracted into compressive relation with the rubber expander ring prior to Contact thereof with the honing stones.

The honing apparatus is shown as supported by a rectangular box-like base 15 which is preferably open at one side for access to parts of the mechanism housed within the base. This base carries a sheet metal top 16 the edges of which are flanged upwardly to retain any kerosene dropping thereon. This top 16 supports a thick metal plate 18 which forms the bed or base plate of the apparatus.

The piston rings 2t), individually or in a group of as many as six, are reciprocated and rotated in contact with the honing stones and to effect such rotation a hydraulic motor 2l. is shown as mounted on the base 22 of a pedestal 23, carried by the bed or base plate 18, this pedestal being formed to provide a horizontal hollow arm 24. The mechanism contained within this arm 24 and the post and cylinder carried thereby is identical to the mechanism shown and described in my said Patent No. 2,530,615 and this detailed description is not repeated, reference being made to this patent for such detailed description. In general, as in the patent, in this arm 2li is suitably journalled a longitudinal horizontal shaft Z5, a pulley 26 being fast to the rear end of this shaft and connected by a drive belt 28 with a pulley 29 fast to Vthe shaft of the hydraulic motor 2l. A worm 30 is fast to the forward end of the shaft 25, this worm being housed within the outer or forward end of the arm 24 `and meshing with-a worm gear 31 which is journalled in the outer or forward end of the arm 24 to rotate about a vertical axis.

This worm wheel 31 is splined to a vertical shaft 36 so that this shaft is capable of vertical reciprocation in the hub of the worm gear 31 but is compelled to rotate therewith. To reciprocate this vertical shaft 36, a tubular post 38 is mounted on the outer or forward end of the arm 24, this tubular post in turn supporting a hydraulic cylinder 39 in coaxial alinernent above the shaft 36. A piston 4t) is arranged in this hydraulic cylinder 39, the piston rod 4l of which extends upwardly through a gland or stufiing box 43 in the upper end `of the hydraulic cylinder. Oil or other liquid is introduced into and exhausted from the upper end of the hydraulic cylinder 39 through a line d4 and is introduced into and exhausted from the lower end of the hydraulic cylinder through a line 4S. The lower end of the piston rod 4l is connected by a coupling 50 with the upper end of the splined shaft 36. As shown in greater detail in my said patent, in which the same reference numbers are used, this coupling compels the splined shaft 36 to reciprocate vertically with the piston rod 41 but leaves .this splined shaft free to rotate independently of this piston rod.

The lower end of the splinedshaft 36 is formed to provide an annular outwardly 'extending iiange or head 52 and a stub extension 53 projecting coaxially downwardly below this head. This stub extension includes an upper pant 54 of large diameter having a radially outwardly projecting bead 55 at its lower end and also includes a coaxial downwardly projecting piloting stem 56 which is of relatively small diameter and is preferably provided with a taper 56 at its lower extremity.

Around the upper part 54 of the stub extension 53 is arranged a at rubber ring 59 which fits against the underside of the flange or bead 52 of the splined shaft 36. This rubber ring 59 is preferably made of synthetic rubber, such as neoprene, to resist the destructive effect of kerosene. A met-al piston ring holding collar or member 60 is .held against the underside of the rubber ring 59 by an annular series yof screws 61 extending through this collar 60 upwardly into the flange 52 and the bore of this collar or holding member' 60 is fitted around the bead 55 at the lower end of the upper part 54 ofthe downward stub extension 53 of the splined shaft 36.` The lower end of this collar or holding member 6ft is of reduced diameter to provide a rabbet 62 in the at under face of this collar or ring extending to the periphery of the collar or ring. In this rabbet 62 is arranged a rubber expander ring 63 also preferably made of a synthetic rubber resistive to any adverse effects of kerosene. As best shown in Fig. l0, in the unstressed condition of this rubber expander ring 63, it is slightly less in vertical thickness than the total vertical thickness of the ring or rings 20 embracing it, this differential in thickness being in the order of, say, from .005 to .010 inch. At rthe same time the outside diameter of this rubber expander ring is, say, .005 inch larger than the inside diameter of the completely closed ring or rings 20. This is for the purpose of insuring adequate clamping pressure against the ring or rings 20 `and at the same time to obtain effective expansive force from the iubber expander ring 63 when the piston ring or rings 20 are contracted into compressive relation with [the rubber expander ring 63 as hereinafter described.

Particularly with the rubber expander ring 63, it has been found that the piston rings 20 have a tendency to 4 adhere or hang up on the rubber expander ring after they have been honed or finished. This is a serious condition because after each ring 2li has been finished the splined shaft 36 is elevated and in such elevation the collar or holding member 60 is withdrawn from the finished ring which is thereafter removed horizontally along its supporting surface. If a finished ring 2li hangs up on or adheres to the rubber expander ring 63, this rubber expander ring cannot receive the next ring to be finished and ring breakage will occur. To prevent the finished piston rings 20 from so hanging up or adhering to the rubber expander ring, an annular series of vertically sliding piston ring ejection pins 65 are provided in vertical slideways through the collar orholding member 6i) near the periphery thereof. The lower ends of these pins are rounded and rest on top of the piston ring 20 being ground. The upper end of these pins are provided with heads 66 which, in the operative or engaged position of the parts as shown in Fig. 5, are disposed above the upper face of the collar or piston ring holding rnember 60. These heads support a loose weight ring 68 which surrounds and is centered by the flange or head 52. When this flange or head 52 rises the weight ring 68 pushes the pins 65 down and these in :turn push the finished piston ring 2t) off of the rubber expansion ring 63.

The piloting stem 56 of the head or 'liange 52 enters a vertical bore or socket 69, which it closely fits, at the upper end of a vertically sliding and rotatable plunger 70. This bore or socket 69 is in an upwardly extending reduced neck 71 on this plunger and which neck provides an annular shoulder supporting a metal collar or plate 72. which forms a companion lower piston ring holding member to the upper piston ring holding member 60. This last piston ring holding member or plate '72 is secured to the plunger 70 by an `annular series of screws 73 and its upper face supports the piston rings 20 while they are being honed. It will be seen that the piston ring holding members 72, 60 provide separable holdingrnembers between which the piston rings 20 being finished are held by the rubber expander ring 63 which is expanded by the movement of these holding members 72, 60 toward each other.

The plunger 70 fits in an open ended vertical cylinder 75, this cylinder being arranged coaxially within and supported by a surrounding cylindrical jacket or shell 76. This shell is shown as integral with and depending from a base plate 78 and projects through an opening '79 through the ithick metal bed plate 13 on which the base plate 78 rests. The cylinder 75 and surrounding jacket or shell 76 are also preferably integral and are connected by a horizontal integral annular partition 80 which forms an open topped sump 81 in the bottom of the base plate 78 surrounding the upper end -of the cylinder 75 and an enclosed chamber 82 surrounding the lower end of the cylinder 75. The sump 81 can be provided with a drain 83 and the upper end of the enclosed chamber 82 can be provided with a vent plug 84.

An opening 85 in the bottom of the chamber 82. is preferably closed by a plate 86 shown as secured by screws S8 and into which is screwed a threaded nipple 89 at the upper end of a tube 90, the nipple 89 establishing communication between the enclosed chamber 82 and the interior of the tube 9). An oil reservoir 91 is secured to and communicates with the lower end of this tube 90 and this reservoir contains an air bladder 92. This bladder is fiexible walled and filled with air which is, of course, compressed to the same pressure as the surrounding liquid 93 which also fills the chamber 82and tube 99.' Accordingly as the plunger 70 is forced down the oil displaced from the chamber 32 compresses the bladder 92 which provides the backpressure to return the plunger 70 to its elevated position. The bladder 92 is prevented, if loose, from Asealing the opening at the lower end of the tube 90 by a bale guard 94 and the oil reservoir 92 can be provided with a drain 95 and oil line 96 by which the pressurized oil used in this reservoir can be maintained at the desired pressure and this pressurized oil also used for other purposes as hereinafter described.

The upward movement of the plunger (Fig. 3) is limited by an end plate or head 98 which can be secured by screws 99 to its lower end and which plate or head 98 engages the lower end of the cylinder 75 in the upper position of the plunger 70. Escape of oil past the piston 70 is also preferably prevented by a stufhng box or gland 100 at the upper end of the cylinder 75 around the plunger 70. Any oil which does escape the stuting box 100 is returned to the sump by a` cylindrical sleeve 101 secured to and depending from a circular flange 102 at the upper end of the plunger 70.

An annular elevated base 105 is provided for the honing stones, this base comprising an annular top 106, a depending marginal wall or skirt 108 and a base flange 109 which can be secured by screws 110 to the thick metal plate 1S in embracing relation to the base plate 78. This honing stone base is provided with a coaxial central aperture 111 surrounding the upper end of the plunger 70, and the margin of this aperture is formed to provide an upwardly facing circular pocket 112 in which a wear disk 113 is titted. This wear disk also has a central opening 114 for the upper end of the plunger 79 and this wear disk supports the honing stones 115.

As best shown in Fig. 6, four of these honing stones 115 are provided in radial arrangement about the axis of the splined shaft 36 and plunger 70 and their respective piston ring holding heads or members 60 and 72. Each `of these stones is in the form of a cube with one vertical semicylindrical face 116 concentric with the faces 116 of the other stones, and with the opposite vertical face 118 secured to the cross head 119 of a stone holder 120. Each stone holder also includes a square shank 121 which extends radially with respect to the axis of the splined shaft 36 and plunger 70 and which rests on the top 106 of the elevated base 105 for the honing stones.

The square shank 121 of each of the honing stones 115 is guided for longitudinal movement radially of the axis of the splined shaft 36 and plunger 7 0 by a U-shaped guide 125 which, as best shown in Fig. 2, includes a pair of side `walls 126 which can be integral with the base 105 for the honing stones and connected by a top plate 128 which can be removably secured by screws 129.

The outer end of the shank 121 of each stone holder 120 is provided with an upwardly facing recess 130 in which is arranged a roller 131. This roller rotates about a vertical axis. Each stone holder 120 is biased radially outward by a pair of helical tension springs 132. As best shown in Fig. 2, one end of the tension spring 132 of each pair is secured to a lug or ear 133 at the end of each cross head 119 of the stone holder 120 and the other end is secured to a lug or ear 134 fast to the corresponding side wall 126 of the corresponding U-shaped guide 125. It will therefore be seen that the several pairs of helical tension springs 132 bias the square shanks 121 radially outwardly along the ways provided by the top 106 of the base 105, and side walls 126 and top plates 128 of the U-shaped guides 125.

This biasing of the stone holders 120 radially outwardly urges the rollers 131 thereof severally into engagement with cams 135 fast to the inside of an adjusting ring 136. This adjusting ring rests on the upper faces of ears 133 integral with and projecting radially from the base 105 for the honing stones as best shown in Figs. 2 and 3, and each of which is in line with a corresponding stone holder 120 and carries and upstanding roller 139, these rollers holding the adjusting ring 136 concentric with the axis of the splined shaft 36 and plunger 70. The working faces 140 of the cams 135 are uniformly eccentrically disposed with reference to axis of the adjusting ring 136 and are pitched in the same direction and it will therefore be seen that rotating the adjusting ring, counterclockwise `as `vie-wed in Fig. 2, will rotate the cams to force all of the stone holders 120 radially inwardly at the same rate and thereby uniformly adjust the semicylindrical working faces 116 of the stones 115 inwardly toward their common vertical axis.

This rotary adjustment of the adjusting ring 136 can be effected in any suitable manner, as by the provision of gear teeth 142 along a part of one side of the adjusting ring and engaged by a gear (not shown) turned by a hand wheel 143, both the gear and hand Wheel being rotatively mounted on a bracket 144 carried by the base 105 for the honing stones.

With each such inward adjustment of the honing stones 1,15 it is, of course, desirable to dress their semicylindrical working faces 116 to a common vertical axis concentric with the axis of the splined shaft 36 and plunger 70. To effect such stone dressing, the lower piston ring clamping member 72 is provided with a radial bore 1.45 which, as best shown in Figs. 5 and 6, carries the cylindrical holder 146 for a cutting tool or diamond 148 projecting from its outer end. The degree of projection of the diamond 148 can be adjusted by a set screw 149 which determines the radial position of the holder 146. It will be seen that each time the stone holders 120 are adjusted inwardly the cutting tool or diamond dresses the stones 115 thereof to a common Vertical axis concentric with the axis of the splined shaft 36 and plunger 70.

The rings 20 to be ground are automatically and successively fed to the upper and lower piston ring holding members 60, 72 to be rotated and reciprocated in contact with the semicylindrical working faces 116 of the group of stones 115. between these holding members by sliding them along a table 150, in synchronism with the operation of the hold ing members. This table is secured, as by screws 151, to upstanding ribs or lugs 152, integral with and extending radially inwardly of the wall 108 of the base 105 for the honing stones. The piston ring table is generally circular, having preferably a rounding extension 1.53 concentric with the vertical axis of the splined shaft 36 and plunger 70 and on its opposite sides having a cut-out or recess 154 through which the honed rings 20 fall to a chute 155 which, as best shown in Fig. 3, comprises an upper inclined part 156 secured to the underside :of the piston ring table at the inner end of the recess 154 and terminating in a generally vertical skirt having a rear wall 158, and side and bottom walls 159, 160, respectively, these latter defining a side opening 161 through which the honed piston rings slide from the incline 156 to a suitable receptacle (not shown). The piston ring table 150 is also preferably provided with a raised rim 162 encompassing its sides, except at the cut-out or recess 154, and also its extension 153.

In Iregister with the pist-on `ring holding members 61), 72, `the pis-ton ring table 150 .is provided with a tapered opening 162. The shape of this tapered vopening is :irnportant in obtaining a free and uninterrupted transfer `of the piston `rings 20 from .the table 150 to between the piston ring holding members 60, 72. rlhus, as best shiown in Fig. 5, this opening 162 is circular and its lower part 163 tapers to provide an upwardly enlarging cone with a taper of 7 with reference tio its axis. The uppermost pant of this lcone has its rim beveled, .this bevei enlarging conically upwardly -at .an angle of 40 with reference to its axis. 1t has been found that the opening 162 must be Lheld quite close to these Idegrees of taper to accept pist-on rings 20 dropped `into the opening to be gripped by the piston ring holding members 60, 72.

A piston ring receiving, feeding and dischanging plate or disk 165 is rotatably mounted on the piston ring table 150 in eccentric relation to the opening 162 so as to feed a succession of piston rings 20 tto this Iopening in timed relation to the movement .of the piston ring holding mem- .bers 60, 72. For this purpose this disk 165 is provided with an annular series `of holes 166 of a size to receive The rings are so fed to and removed from loosely the piston rings and positioned to successively register with the opening 162.

The piston .ring conveying disk is shown as provided with a center opening 168 in which is fitted a hub cap 169 the rim of which extends' over the piston ring conveying disk .165 andycan be secured thereto as by rive-ts 170. This hub cap is fixed, as'by screws 171, to the upper flange 172 of a sleeve 173 rotatably mounted ion an upright spindle 174 and arranged in a circular `opening 175 through the piston ring table 159.

At .the .rim of this flange 172 the hub cap 169 is provided with a downwardly .opening annular groove 176 and in this groove, as best shown in Fig, 4, is arranged a packing ring 178 which is interposed between the rim of -the flange 172 and the rim of the hole 175 and which acts as a dam to prevent oil on the piston lring table 15d `from passing lfrom under the piston ring conveying disk 165 through .the opening 175.

The lower end of the sleeve 173 is formed to provide a pinion 18! and to the underside of this pinion is secured, as by screws 181, a star-wheel 182. The hub of this star-wheel rests on a step bearing 183, this step bearing in turn being .supported on an elevated part 184 `of .a base casting 185 .secured on top of .the thick metal plate 18. The spindle 174 extends through this casting and is secured thereto by a nut 186 and washer 188 and the upper end of this spindle is reduced and threaded to receive a nut 189 and lock nut 19t?, the nut 189 bearing against a friction cap 191 and thickened rim .of which bears against the hub cap 169 of the piston ring conveying -disk 165.

The pinion meshes with a pinion 195 having its hub loosely mounted on a vertical shaft 196. This shaft has a lower reduced end journalled in a ball bearing 193 carried by the base casting and an upper reduced end journalled in a ball bearing 199 carried by an arm or bracket 20() removably secured to this base casting 185. The pinion 195 has a concentric cylindrical recess or pocket 201 in its underside and this pocket is enclosed by a bottomV disk 202 secured, as by screws 203, to the rim of the pinion 195.

The pocket 201 houses the driving member 205 of .a one-way clutch, the pinion 195 being the driven member thereof. As best shown in Fig, 7 this driving member 205 is of generally cylindrical shape and ts the cylindrical pocket and .at spaced intervals along its rim .is provided with V-shaped notches 206 one Vside of which is radial with reference to the axis .of the clutch and the `other side of which is parallel with a tangent at the line of juncture between the radial face of Ithe notch and the rim of the driving member 205. A ball or .roller 207 4is arranged in each notch 266 .and is urged by a small helical compression spring 208 into wedging relation between the notch 206 and the wall forming the pocket 2111. The driving member 205 of the one-way clutch is fast to the shaft 196 and it will be seen that 'when the .shaft 196 and driving member 205 are driven in .one direction (clockwise as viewed in Fig. 7) the balls' 297 wedge and drive the pinion 195 but that when the shaft 196 and driving member 265 .are driven in the opposite direction (counterclockwisc as viewed in Fig. 7) the balls 297 unwedgc and do not drive the pinion 195.

Another pinion 209 (Fig. 3) is fast to Vthe lower end of the .shaft 196 .and meshes with the teeth of a horizontal rack 210. One end Iof lthis rack (Fig. 8) is shown as having a lar-ge end bor-e 211 in which is tted a iixed piston 212. This fixed piston in turn has an axial through bore 213 the inner Lend of which communicates with vthe large end bore 211 and the outer end of which 4is connected by a fitting 214 with an .oil line 215. The fixed piston 212 has a -reduced threaded neck 216 extending through .a block 218 and to which block the neck 216 and piston 212 are secured by a nut 219. The block 213 is secured, as by screws 220, to the end of an inverted U- shaped bracket 221 and depending side legs of which are 8 provided with base anges 222 secured, .as by screws 223, to .the plate 18. The interior `of the inverted U-shaped bracket 221 forms a guide way 224 for the corresponding end of the rack 210. l,

Similarly :the other end of this 1rack 219 is shown as `having a small end bore 231 in which is iitted a fixed piston 232. This fixed piston in turn has an axial through bore 233 the inner end of which `ctirnrnunicates with the large end bore 231 and the outer end of which .is connected by a fitting 234 with .an oil line 235. The fixed piston 232 has a reduced threaded neck 236 extending through a block 238 and `to which block the neck 236 and piston 232 are secured by a nut 2319. The 'block 238 is secured, as by screws 240, to the end fof an inverted lJ-shaped bracket the depending side legs `of which are provided with hase flanges 262 secured, as by screws 243, :to the plate 1S. The interior of the .inverted U-shaped bracket 241 forms .a guideway 244 for the corresponding end .of the rack 210. it will be seen that when equal toil pressures are applied to the lines 215 and 235, because `of the preponderating size of the xcd piston 212, the rack 216 will be driven downwardly as viewed :in Fig. 8 thereby .to rotate the pinion 269, shaft 196 and driving member 265 ofthe clutch in a clockwise direction as viewed in Fig. 7.

The rack 210 also carries a stop block 45 .arranged t0 engage the teeth 25.6 of the star-wheel 132. It will be noted that -this star-wheel always rotates counter-clockwise as viewed in Fig. 7 and that the teeth correspond in number to the number `of piston ring receiving holes 166 of the piston ring conveying disk 165. it `will .also be noted that the teeth 246 of the star-wheel `form rectangular notches 24S exactly conforming to the working corner of the stop `block 245.

The piston rings 2t? are automatically fed from a stack 2d successively into the piston ring receiving holes 166 of the. piston ring conveying disk 165. This stack is held on the piston ring conveying disk 165 in line with its holes 166 so that as this disk is rotated each hole slides one or more piston rings 2t) from the bottom of the stack Ztl', the number being determined by the thickness of the disk 165. The stack holder can be of any suitable construction but is shown in TFigs. l and 2 as constructed as follows:

The numeral 2711 represents a plate in the form of a rim having a large central opening 271. This plate is held in spaced relation above the piston ring conveying disk 165 and is mounted on a stationary part of the machine. For this purpose one side or edge of this plate is shown as secured, as by screws 273, to a bracket 274 which is secured to the base casting 15. This plate 27d has three vertical screws 275 at spaced intervals around the opening 271 and the heads of each of which clamp downwardly the horizontal bifurcated arm 276 of an L-shaped slide 278. Each slide has an inner vertically extending part 279 which carries a vertical rod 280. The screws 275 are loosened and the L-shaped guide adjusted so that their rods 280 closely embrace the sides of the stack 20' and hold this stack in vertical alinement with the passing openings of the piston ring conveying disk 165.

The oil pressures for driving the machine can be supplied from a pump 285 driven by an electric motor 286. The oil lines to the hydraulic motor 21 are indicated at 288 and 289.

Operation During the operation of the machine, the upper piston ring holding member 6i) is continuously rotated. This rotation is eiiected by the hydraulic motor 21 (Fig. l) powered through the oil lines 238 and 289. This hydraulic motor through the pulleys and belt 29, 28, 26 drives the shaft 25 and through the worm 3&1 and worm gear 31 drives the shaft 36 splined to this worm gear.

The rotation of the splined shaft 36 (Fig. 5) rotates the upper clamping member 60 which is secured to the lower end of the shaft by the screws 61. A more detailed showing of this drive is contained in my Patent 2,530,615.

`The piston rings 20 to be honed are gathered into the stack 26 and this stack is placed lamong the rods 280 (Figs. 1 and 2) so that the lowennost piston ring 20 is on the piston ring conveying disk 165. These rods 280, when adjusted, are stationary and are adjusted, by loosening of the screws 275 and shifting of the bifurcated arms 276 of the L-shaped holders 275, for these rods so that these rods hold the stack 20 of piston rings in line with the passing holes 166 of the piston ring conveying plate or disk 16S. Accordinglytas this conveying plate or disk 165 rotates about its concentric axis, as each of its holes 166 passes under the stack 20', the lowerrnost ring or rings of the stack drops into this hole and continued rotation of the disk 16S displaces one or more piston rings 20 from the bottom of the stack 20', the number being determined by the thickness of the` piston ring conveying disk around the holes 166. The drawings illustrate the piston rings as being withdrawn two at a time from the bottom of the stack 20.

This piston ring conveying disk is rotated intermittently, in synchronism with the operation of the piston ring holding members 60, 72 in honing the piston rings, to feed the assumed pair of piston rings 26 to be honed onto tbe lower piston ring holding member 72 while the holding members 66, 72 are separated, to remove the honed pair of piston rings 20 from this lower piston ring holding member 72 while the holding members 60, 72 are separated, and to convey the honed piston rings 26 to the cut-away or recess 154 (Figs. 2 and 3) where they fall by gravity into the chute 155.

To impart such intermittent or step-by-step synchronized movement to the piston ring conveying disk 165, oil under the same pressure is introduced into the lines 21S and 235 (Fig. 8). Since the stationary piston 212 is larger than the stationary piston 232, the luid pressures in the cylindrical bores 211 and` 231 at opposite ends of the rack 210 drives this rack downwardly as viewed in Fig. 8 or the right as viewed from the front of the machine. This rotates the pinion 269 and its shaft 196 clockwise as viewed in Fig. 8 and hence rotates the driving member 205 of the clutch clockwise as viewed in Fig. 7. This clockwise movement of the driving clutch member 205 causes its balls 297 to wedge against the walls of the cylindrical pocket 201 of the pinion 19S and hence imparts a similar clockwise rotation to this pinion. This imparts a counterclockwise rotation to the pinion 180, also as viewed in Fig. 7, and which meshes with the pinion 195. Since` this last pinion 180 (Fig. 3) is integral with the sleeve 173 to the upper end of which the hub cap 169 of the piston ring conveying disk 165 is secured, this rotates this piston ring conveying disk 165' counterclockwise as viewed from the top (Fig. 2).

It is essential that the step-by-step movement of the piston ring conveying disk 165 be stopped exactly as each hole 166 therein comes into register with the separated piston ring holding members 60, '72 (Fig. 3). To insure such stopping of each step-by-step advance of the piston ring conveying disk 165, the counterclockwise rotation of the pinion 180as viewed in Fig. 7, ettects a similar counterclockwise rotation of the'star-wheel 182 which is fast thereto (see Fig. 3). Accordingly as the rack 210, together with its rectangular stop block 245, is moving downwardly as viewed in Fig. 7 or to the right as viewed from the front of the machine, this star-wheel 182 is moving counterclockwise as viewed in this Fig. 7 and one of its rectangular recesses 248 formed by a corresponding pair of its teeth is moving toward mating engagement with the rectanguar stop block 265. When the rectangular stop block 245 is fully mated in one of the rectangular recesses 248 further advance of the piston ring conveying disk 165 bythe rack 210 is impossible and atV this time a corresponding piston ringcarrying `hole. 166

'10 in the pistoh ring conveying disk 165 is in axial register with the piston ring holding members 60, 72.

At this time the continuously rotating splined shaft (Figs. 1 and 5) is reciprocated to seize the pair of piston rings 20 between the holding members 60, 72 and to reciprocate and rotate the pair of piston rings in the zone of action of the honing stones 115.

The downward reciprocation of the continuously rotating splined shaft 36 is eiected by oil pressure through the line 44 (Fig. l) into the upper end of the cylinder 39 and which drives the piston 40 downwardly. Through the coupling 5t) this drives the splined shaft 36 downwardly which splined shaft is continuously rotated by the hydraulic motor 21 as previously described.` Since a pair of the piston rings 20 has been brought to rest by the piston ring conveying disk 165 in a position on top of and concentric with the lower clamping member 72 (Figs. 5 and l0), the downward movement of the splined shaft grips the pair of piston rings 2t) between the holding member 60, fixed to the bottom of the splined shaft 36, and the top holding member 72.

The first effect of this downward movement of the splined shaft 36 and the piston ring holding member 6l) fixed to its bottom (Figs. 5 and l0) is to cause the pair of piston rings 2li to contact and lift the pins 65 relative to the holding member 69. These pins in turn lift the weight ring 68. This weight ring does not come into action until the holding members 6d, '7 2 separate following honing when it returns the pins 65 downwardly to insure ejection of the honed rings 20.

The second eliect of this downward movement of the splined shaft 36 rand the piston ring holding member 66 xed to its bottom is to exert clamping pressure through the piston ring or rings 2t) (Figs. S and l0) against the top face of the bottom holding member 72. T his force is resiliently and movably resisted by the plunger 76. As this force increases because of the continued downward movement of the splined shaft 36 this plunger 70 moves downwardly against the body of oil contained within the chamber S2 (Fig. 3) and this oil is displaced through the tube into the reservoir 91 (Fig. 9). ln this reservoir the displaced oil compresses the air bladder 92, this air bladder supplying the resilient resistance to the downward movement of the piston ring holding members 6l?, 72.

The third effect of this downward movement of the splined shaft 36 and the holding member 6b is to carry the piston ring or rings` 2t) downwardly through the tapered or conical opening 162 in the table 163 thereby to contract the piston ring or rings 26. As previously described the vertical thickness of the rubber expander ring 63 is, say, from .005 to .010 inch thinner than the total vertical thickness of the piston` ring or rings 2G and the outside diameter of this rubber expander ring 63 is, say, .005 inch greater than the fully contracted inside diameter of the piston ring or rings Ztl. Accordingly as the piston ring or rings 2@ reach the contracted bottom or throat of the conical opening 162 the piston ring or rings are contracted into compressive relation with the rubber expander ring 63 which thereby exerts a yielding expansive force on the piston ring or rings 2d as illustrated in Fig. ll.

During this period in which the above three actions are taking place, the splined shaft 36, holding members 60, '72 and plunger 70 are moving downwardly against the resistance imposed by the air bladder 91 (Fig. 9). Accordingly as the piston ring or rings 2li to be honed (Figs. 5, l() and 11) are carried down into the tapered or conical opening 162 in the table 163, if either of the pair of piston rings 20 is suiliciently out of axial aflinement with the holding members 6d, 72, the ring or rings will engage the initial or upper 40 bevel 16d of this conical opening 162 and be displaced toward axial alinement with the holding members 60, 72. Such a misalined piston ring would then encounter the lower or 7 taper 163 of theI conical opening 162 and be nally brought into concentricity with the holding members 60, 72, at the bot-tom of the conical opening. These degrees of taper of the conica-l faces 164, 163 have been found to be quite critical in insuring proper feeding of the rings to the stones. Any substantial departure from these degrees of taper was found to result in ring breakage and hence interruption of the automatic operation of the machine.

On leaving the tapered opening 162 (Fig. 5) the assumed pair of piston rings 2t) are brought into contact with the honing stones 115. Since the splined shaft is being continuously rotated by the hydraulic motor (Fig. l) and since the piston ring holding members 60, 72 Vare now moving downwardly, the pair of piston rings 20 are subjected to both rotary and reciprocatory honing contact with the several semicylindrical working faces 116 of these honing stones 115 and which jointly provide a cylindrical working face. While so in contact with the honing stones, the rings 20 are being urged outwardly into firmer contact with these stones by the radial pressure exerted by the rubber expander ring 63. This pressure is, however, uniform so that there is notendency to hone one part of either` ring Vand not another part.

rl`he hydraulic control (not shown) then reciprocates the spline-d shaft 36 and clamping members 66, 72, a predetermined number of times and that distance required to move the pair of piston rings 20 axially substantially the full height of the working faces 116 of the honing stones 115. This reciprocation is determined by the alternation of uid pressure in the lines 44, 45 to the cylinder 39 (Fig. l), the piston 4t) in which reciprocates the splined shaft 36. At this time this splined shaft, and hence the piston rings 2@ being reciprocated thereby, is being continuously rotated so that the piston rings being honed are subjected to both rotary and recip-rocatory contact with the honing stones. The rate and number, for each honing, of both the rotations and reciprocations of the rings being honed will depend, of course, on the individual characteristics of each particular' type of piston ring.

While in contact with the honing stones, the rings 2i) being honed are pressed uniformly radially outwardly by the rubber expander rings 63 which are under the back pressure of the contracted piston ring or rings 2t). With such radial pressure of the rubber rings 63 the rings are honed rapidly and uniformly, in particular without so called shaking in which the periphery of the rings are irregularly honed because of lack of uniform pressure of different parts of the ring against the honing stones.

As with my prior patent the action of the rubber ring or pad 59 also greatly contributes to the uniformity of the piston ring honing in providing a slight yield in the connection between the upper piston ring holding member 6i) and the rotating and reciprocating splined shaft 36.

After the piston ring or rings have been subjected to the required action of the honing stones 115, the honed piston rings are elevated to the level of the table 150 and back into the hole 166 of the piston ring conveyor disk 165 from which they were transferred into the honing zone. This is effected by introducing oil under pressure into line d (Fig. l) to drive the piston 40 upwardly. Through the coupling 5i), this lifts the splined shaft 36 as well as the upper piston ring holding member 60 secured to the lower end of this shaft. The back pressure of the air lilled bladder 92 (Fig. 9) against the bottom of the plunger 7G (Fig. 3) causes this plunger to rise and maintain contact between the lower piston ring holding member 72 secured to the upper end thereof and the rubber expander ring 63. This follower movement of this lower piston ring holding member continues until the lower end head 98 (Fig. 3) of the plunger 70 engages the lower end of the cylinder 75 at which time the upper face of the bottom piston ring holding member is flush with the upper surface of the table 150.

As the splined shaft 36 and the upper piston ring holding member continue to rise the honed piston rings 20 are left resting on the lower piston ring holding member in the hole 166 of the piston ring conveyor disk 165 from which they were forced downwardly into the zone of action of the honing stones 115.

Occasionally it-was found that the honed piston ring or rings 20 tended to stick to the upper piston ring holding member 60 or to its expander ring 63. To avoid this the honed ring or rings are positively positioned on the flat top of the lower piston ring holding member 72 as the upper piston ring holding member 60 moves away from the lower piston ring holding member 72. Thus the entire weight of the weight ring 68 (Fig. 5), through the pins 65, is resting on the piston rings 20 during the honing operation. When the upper piston ring holding member 60 is withdrawn upwardly from the lower piston ring holding member 60, this weight ring 68 and its pins are permitted to drop and eject the honed piston rings from-the upper piston ring holding member 60 onto the upper face of the lower piston ring holding member 72.

During the above honing operation, oil had been forced through the line 235 (Fig. 8) into the small cylinder 231 and exhausted from the large cylinder 211 through the line 215. Accordingly during the honing operation the rack was returned from the lower position as shown in Fig. 8 (right hand as viewed from the front of the machine) to its opposite position.

Immediately following the separation of the upper piston ring holding member 60 from the lower piston ring holding member 72, oil under the same pressure is introduced into the lines 215 and 235 (Fig. 8) and because of the greater effective size of the cylinder 211 and piston 212, `the rack 210 is moved downwardly as viewed in Fig.`

8 or to the right as viewed from the front of the machine. This rotates the pinion 209, shaft 196 and driving member of the one-way clutch clockwise as viewed in Figs. 8 and 7 thereby to drive the pinion 195 which forms the driven member of this clutch also clockwise as viewed in Fig. 7. This rotates the pinion 180 counterclockwise and since this pinion 180 (Fig. 3) is integral with the sleeve 173 to which the hub cap 169 of the piston ring conveying disk 165 is fast, this rotates this piston ring conveying disk 165 counterclockwise as viewed in Fig. 2.

Since the honed ring or rings 20 have at this time been returned to the corresponding hole 166 of this piston ring conveying disk and are now ush with the t'op of the table 150, the honed ring or rings are slid olf of the upper face of the lower piston ring holding member 72 onto the table 150 and another pair of unhoned piston rings replaced therefor as previously described. The honed piston rings are advanced step-by-step, with each successive feeding of the rings onto the lower piston ring holding member 72 until the pocket or hole 166 containing the assumed rst two pairs of piston rings 20 comes linto register with the recess or cut away 154 at which time the honed pair of piston rings, as shown in Fig. 3, slides down the chute 155 and are discharged from the machine.

As stone wear takes place the honing stones are adjusting inwardly and then dressed to jointly provide a cylindrical working face 116. For this the operator turns the handwheel 143 (Fig. 2) which, through a pinion (not shown) engaging the teeth 142, turns the honing stone adjusting ring counterclockwise as viewed in Fig. 2. This causes each of the cams 135 on this ring to force the rollers 131 toward the axis of honing, these rollers being mounted on the'stone holders 120 (Fig. 3) the Shanks 121 of which are slidingly mounted for longitudinal horizontal movement toward and from the axis of honing in the U-shaped guides 125. These stone holders (Fig. 6) carry the honing stones 1715 and areadjusted radially inwardly toward the axis of honing.

With the machine now operating without piston rings (Figs. and 6) the diamond 148 contacts, with both a rotary and axial movement of the lower piston ring holding member 72, the working faces 116 of the several honing stones 115. Accordingly the stones are dressed to have working faces 116 truly cylindrical and coaxial with the axis of honing. If adjustment of the diamond 148 is required, this can be done by loosening the set screw 149 securing its holder 145.

From the foregoing it will be seen that the present invention provides an automatic piston ring honing machine which hones a succession of piston rings accurately and uniformly and which accomplishes the various objects and has the numerous advantages as set forth.

I claim:

l. Apparatus of the character described, comprising a plurality of abrasive stones jointly providing working faces in opposed circular relation about a vertical axis, an upper ring holding member mounted for movement along said axis, a lower ring holding member movable along said axis and toward and from said upper ring holding member, said ring holding members being arranged to engage and hold a ring arranged therebetween, and means arranged to insure the retention of said ring on said lower ring holding member when said ring holding members are separated, comprising a weight loosely mounted on said upper ring holding member for free vertical movement relative thereto, and means adapted to support said weight on the ring held between said ring holding members whereby when said ring holding members are separated said weight ejects said ring from said upper ring holding member.

2. Apparatus as set forth in claim l wherein said last means comprises an annular series of pins in vertical guideways in said upper ring holding member and adapted to be supported by a ring between said ring holding members and supporting said weight.

3. Apparatus for finishing resiliently expansible rings, comprising a table having a downwardly diminishing conical bore extending vertically therethrough and engageable with the peripheries of said rings, `a plurality of abrasive honing stones below said bore and having vertical working faces arranged in opposing circular relation to one another concentric with said bore and engageable with the peripheries of said rings, a ring conveyer plate on said table having a series of holes extending vertically therethrough and forming with said table pockets adapted to hold and convey a progression of rings on said table, means movably supporting said ring conveyer plate on said table to carry said holes in said ring conveyer plate successively into register with said bore, a pair of ring holding members including an upper member and a lower member mounted for vertical movement concentric with said bore toward and from each other to engage the upper and lower sides of and move a ring from a registering hole downwardly into engagement with said conical bore and thence into engagement with said abrasive honing stones, and means arranged to move said ring holding members away from each other and to bring the upper face of said lower ring holding member into planar relation with said table while said ring conveyer plate is being advanced whereby a honed ring is removed by said ring Iadvancing plate from the upper surface of the lower rim holding member onto said table while an unfinished ring is being moved by said ring advancing plate from said table onto said lower ring holding member.

4. A structure as rset forth in claim 3 wherein one of said ring holding members carries a radially projecting cutting tool which inoudes means arranged to cut and to dress said working faces.

5. Apparatus for finishing resiliently expansible rings as set forth in claim 3 wherein stationary means support a stack of rings on the upper surface of said conveyor plate in the path of said holes whereby as said ring conveyer plate is advanced, -the lowermost ring of said stack drops into each hole onto said table and is removed from the stack along the table bythe continued advance of said ring conveyer plate.

6. Apparatus for finishing resiliently expansible rings as set forth in claim 3 wherein a stationary bracket Iis ysupported above said ring conveyer plate and has an opening successively registering with said holes and wherein a plurality of spaced posts are adjustably mounted on said bracket for adjustment toward and from a common vertical axis, said posts being adapted to support a stack of rings on said yring conveyer pllate in the path of said holes so that as said ring conveyer plate is being advanced 4the lowermost ring of said stack drops into each hole onto said table and is removed from the stack along said table by the continued advance of said conveyer plate.

7. Apparatus for finishing resiliently expansible rings as set forth in claim 3 wherein said table is provided with a circular opening extending vertically therethrough and arranged to register with said holes and positioned so that the finished rings leaving said ring holding members fall from said holes into said circular opening, and a chute arranged to catch the rings falling from said circular opening.

8. Apparatus for finishing resiliently expansible rings as set forth lin claim 3 having means adapted to advance said -ring conveyer plate step-by-step including a one-way clutch having its driven part operatively connected with said ring conveyer plate, a rack operatively connected with the driving part of said one-way clutch, one end of said rack being formed to provide a large cylinder and the opposite end of said rack being formed to provide a small cyllinder, a fixed piston in each of said cylinders, and means `arranged to introduce fluid under pressure through said pistons into said cylinders.

9. Apparatus for finishing resiliently expansible lrings as set forth in claim 3 having means adapted to advance said ring conveyer plate step-by-step including a one-way clutch having its driven part operatively connected with said ring conveyer plate, a rack operatively connected with the driving part of said one-Way clutch, means arranged to reciprocate said rack, a star wheel operatively connected with said driven part of said clutch, and a stop on said rack and mating with a tooth of said star wheel when a corresponding hole of said ring conveyer plate is in register with said bore.

l0. Apparatus for finishing resiliently expansible rings as set forth in claim 3 wherein a resilient expander ring is mounted on one of said ring holding members in position to enter the resiliently expansible ring to be finished held between said ring holding members, said ring holding members jointly forming with the resiliently expansible ring to be finished an annular chamber containing said resilient expander ring and said resilient expander ring being compressed when said resiliently expansible ring to be finished is contracted radially by movement along said diminishing conical bore to exert radially outward force against said resiliently expansible ring to be finished.

References Cited in the le of this patent UNITED STATES PATENTS 175,653 Bliss Apr. 4, 1876 1,041,406 Bauroth Oct. l5, 1912 1,047,373 Bond Dec. 17, 1912 1,493,131 Stevenson May 6, 1924 1,501,317 Donaldson July 15, 1924 1,511,165 Jaeger Oct. 7, 1924 1,683,867 Copland Sept. 11, 1928 1,693,778 Engman Dec. 4, 1928 2,138,257 Sievers Nov. 29, 1938 2,283,503 Johnson May 19, 1942 2,343,407 Galloway Mar. 7, 1944 2,360,528 Talmage Oct. 17, 1944 2,458,854 Hull Ian. 11, 1949 2,530,615 Hutto Nov. 21, 1950 2,695,583 Swarr Nov. 30, 1954 

